Effect of Sliding Speed on the Thermal Fields and Frictional Behaviours of Asbestos-free Frictional Materials Used for Dry Clutch System

Abstract

Abstract Friction materials are utilized in systems that require explicit contact interaction between at least two components. The requirement to obtain successful frictions materials (high resistance for thermal and wear) is very difficult to such an extent that the market for friction devices is about seven billion dollars for each year. Common applications of the friction materials are automotive clutches and brakes systems where frictional materials play a significant role in these systems. In clutch systems, the tribological contact under sliding condition during the engagement maneuver is strongly affected by the frictional heat generated occurring in the system. Owing to the sliding between the contacting parts, this will lead to produce the mechanical energy losses, which are converted in heat with ensuing temperature increase. The magnitude of temperature rise depends on the complex interaction between frictional characteristics of materials, contact pressure, sliding speed, thermal properties of contacting materials. During the early stage of engagement of friction clutch, high energy is dissipated due to slipping between the contact surfaces. Hence, the surface temperature of the clutch elements is increased due to generated frictional heat. In turn, non-uniform deformation is produced which influence the pressure distribution and thermal field. In other word, the contact pressure and high temperatures will be concentrated in small area of the contact zone that accelerates premature failure of the clutch system. Unfortunately, only few literature works explore through experiments the influence of temperature and other influent variables on the frictional behaviour of the clutch facing materials. In this study, the effect of sliding speed on temperature field and frictional behaviour of ceramic clutch pad was investigated to find out the safely working zone of dry friction clutch systems.